Just noticed this on eBay, from Merideth Instruments. They're surplus optics mounts for laser shows. You get 10 for $35 shipped, which is not bad considering the adjustable mounts in the lot can go for $30 each in some places. I nabbed two sets.

There are four cylinder lenses (NOT line-generating unless you consider ~1-inch a line), one long FL meniscus lens, two FS mirrors, and three dichros that reflect red and pass green and blue. But they are sometimes frosted on the back and therefore useless unless you want to use them to just reflect red.

These are a pretty good buy for the price, considering usual going price for optics mounts.
I have noticed that they have been dropping their prices all around lately.
If only I had disposable income right now.